System and method for cooling computing devices within a facility

ABSTRACT

A system for cooling computing devices within a facility includes an air inlet that delivers cool air to a supply air space within the facility, an exhaust air damper that is configured to exhaust heated air from an exhaust air space within the facility, and computing devices that are arranged within the facility to at least partially partition the supply air space from the exhaust air space. The system also includes an air filter that is configured to filter the cool air and a mixing damper that is positioned within the interior space of the facility and that is operable to control an amount of exhaust air that is mixed with the cool air. The cool air and/or a portion of the exhaust air are used to cool the computing devices and airflow through the system is substantially driven by fans of the computing devices.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.16/053,648, filed on Aug. 2, 2018, entitled “SYSTEM AND METHOD FORCOOLING COMPUTING DEVICES WITHIN A FACILITY,” the content of which isincorporated by reference herein in its entirety.

BACKGROUND

Relatively large facilities are commonly used to house computingdevices, which may function as data or processing centers. Theincreasing use of online computing and cloud computing services hasgreatly increased the demand for such facilities. The use of computingdevices in the blockchain art has likewise increased the demand forcomputing device facilities. The substantial amount of computing deviceswithin a facility often results in substantial heat generation withinthe facility due to the appreciable power requirements of the computingdevices, which can be in excess of 30 kilowatts per linear foot ofcomputing space. Various means have been used to cool such facilitiesincluding the use of conventional HVAC systems, liquid cooled systemsand the like.

BRIEF SUMMARY

The embodiments described herein relate to a system and method forcooling computing devices within a facility. According to one aspect, asystem for cooling computing devices within a facility is described. Thefacility has an interior space that includes a supply air space and anexhaust air space. The supply air space is configured to supply cool airto the computing devices to cool the computing devices during operationof the computing devices. The exhaust air space is configured to exhaustor vent heated air generated from the computing devices inside thefacility to the external environment. The system includes an air inletthat is coupled with an exterior wall of the facility and that isconfigured to deliver cool air to the supply air space from the externalenvironment. The system also includes an exhaust air damper that isconfigured to exhaust the heated air from the exhaust air space to theexternal environment. The system further includes a plurality ofcomputing devices that are arranged within the interior space topartition at least a portion of the supply air space from the exhaustair space. Some, most, or substantially each of the computing devicesinclude a fan that is capable of moving the cool air across one or moreheat generating components of the computing device to cool the heatgenerating components.

The system additionally includes an air filter assembly that ispositioned between the supply air space and the computing devices. Theair filter assembly is configured to filter the cool air that issupplied to the computing devices from the air supply space. The systemalso includes a mixing damper that is positioned within the interiorspace of the facility between the supply air space and the exhaust airspace. The mixing damper is operable to control an amount of exhaust airthat is supplied from the exhaust air space to the supply air space formixing with the cool air supplied through the air inlet. Airflow throughthe system is substantially or entirely driven by the combined airflowof at least a plurality of the fans of the computing devices.

According to another aspect, a method of cooling computing deviceswithin a facility is provided. The facility has an interior space thatincludes a supply air space and an exhaust air space. The methodincludes flowing cool air from an external environment through an airinlet of an exterior wall of the facility to supply the cool air to thesupply air space. The method also includes flowing the cool air throughan air filter assembly to filter the cool air and thereby removeunwanted particles and debris from the cool air. The method furtherincludes flowing the filtered cool air through a plurality of computingdevices that are arranged within an interior space of the facility sothat the computing devices partition at least a portion of the supplyair space from the exhaust air space. Some, most, or substantially eachof the computing devices include a fan that is capable of moving thefiltered cool air across one or more heat generating components of thecomputing device to cool the heat generating components and heat thefiltered cool air. The heated air flows into the exhaust air space fromthe computing devices subsequent to cooling the heat generatingcomponents. The method additionally includes flowing the heated airthrough an exhaust air damper to exhaust the heated air from the exhaustair space to the external environment. Airflow of the cool air and theheated air is substantially or entirely driven by the combined airflowof at least a plurality of the fans of the computing devices.

BRIEF DESCRIPTION OF THE DRAWINGS

The present technology is described in conjunction with the appendedfigures:

FIG. 1 illustrates an embodiment of a system that is designed to coolcomputing devices within a facility.

FIGS. 2-3 illustrate an embodiment of a section of the facility of FIG.1.

FIG. 4 illustrates an embodiment of airflow through the section of FIGS.2-3 in which exhaust air is not recirculated within the section.

FIG. 5 illustrates an embodiment of airflow through the section of FIGS.2-3 in which exhaust air is recirculated within the section.

FIG. 6 illustrates another embodiment of a section of the facility ofFIG. 1.

FIG. 7 illustrates a method of cooling computing devices within afacility.

In the appended figures, similar components and/or features may have thesame numerical reference label. Further, various components of the sametype may be distinguished by following the reference label by a letterthat distinguishes among the similar components and/or features. If onlythe first numerical reference label is used in the specification, thedescription is applicable to any one of the similar components and/orfeatures having the same first numerical reference label irrespective ofthe letter suffix.

DETAILED DESCRIPTION

The ensuing description provides exemplary embodiments only, and is notintended to limit the scope, applicability or configuration of thedisclosure. Rather, the ensuing description of the exemplary embodimentswill provide those skilled in the art with an enabling description forimplementing one or more exemplary embodiments. It being understood thatvarious changes may be made in the function and arrangement of elementswithout departing from the spirit and scope of the invention as setforth in the appended claims.

The embodiments described herein relate to a system and method forcooling computing devices within a facility. In particular, the systemis designed to cool computing devices that are involved in processesrelated to blockchain technology, such as “mining” or participating inproof-of-work processes that are known in the blockchain art. The systemand method may be particularly useful in cooling computing systems thatare participating in cryptocurrency mining.

The term computing device as used herein is meant to cover any devicethat performs computing operations and may include personal computers,servers, host devices, central processing unit (CPU) devices, graphicsprocessing unit (GPU) devices, field programmable gate array (FPGA)devices, application-specific integrated circuit (ASIC) devices, adedicated mining device, any combination of said devices, and the like.

The systems and method described herein use outside ambient air to coolthe computing systems. Unlike traditional systems, the cooling system isnot designed to cool the outside air with conventional heating,ventilation, and air conditioning (HVAC) components, such as acompressor, an evaporator coil, a condensing coil, an expansion valve, acooling room air conditioner (CRAC), a chiller, a cooling tower, directexpansion refrigeration, etc. Rather, 100% of the air that is used inthe system is provided from the external environment. The air that isheated by the computing devices may be recirculated and combined withthe cool air when the cool air is too cold or when the humidity in thecool air is too high. But the air that is used in the system is notcooled by conventional HVAC systems. As used herein, the term “cool air”refers to air that is supplied from the environment surrounding thefacility. The outside air that flows into the facility may be termed“cool air” to differentiate the outside air that enters the facilityfrom the air that remains outside the facility. The cool air is ambientair in the environment and thus, the cool air is the same temperature asthe air surrounding the cooling system facility. The temperature of thecool air is lower than the temperature of the computing systems, but mayvary drastically depending on the season, weather conditions, and/orother environmental conditions. For example, the temperature of the coolair may vary between 0 and 95 degrees Fahrenheit or more.

In addition, the system typically does not include a dedicated fan,dedicated fans, or a dedicated blowing mechanism that is designed topush air through the system. Rather, the airflow through the system isgenerated by one or more fans of the computing devices, and typicallysome combination of computing device fans. The cooling effect of thesystem is achieved through a combination of the facility design and thecombined effect of the computing device fans. Stated differently, thefans of the computing devices (e.g., servers, CPUs, GPUs, etc.) push theair through the system. In such instances, the system does not includeany other fans or air moving devices other than the fans of thecomputing devices. As such, the system is a completely passive system inthat the fans of the computing device drive airflow through the systemand in that the cooling is achieved via convective cooling from the coolair, which in some instances is recirculated in the system after coolingthe computing devices. In other embodiments, the system may include oneor more dedicated fans that aid the computing device fans in pushing theair through the system.

Since the airflow through the system is dependent entirely, oressentially entirely, on the computing device fans, the system isdesigned to minimize pressure losses or pressure drops as the air flowsthrough the system. This is achieved, in part, by maximizing the inflowof air from the environment, and/or the air that is recirculated in thesystem, and by employing low pressure drop filters, largecross-sectional areas within the facility, and other components. In thismanner, the computing device fans do not experience undue stress inpushing the air through the system. The system is also designed tominimize or prevent the formation of vortices, unless explicitlyrequired to counteract airflow stratification, in order to increase andmaintain the flow of air through the system.

As briefly mentioned above, the system is further designed so that theheated air may be recirculated within the system and combined with freshoutside air from the external environment. The heated air may becombined with the fresh outside air to treat the fresh outside air to aspecific target temperature and/or environmental humidity condition byraising the temperature of the fresh outside air. The system isautomated to open one or more dampers, or airflow valves, when thesystem determines that the temperature of the outside air is too low orthat the relative humidity of the outside air is too high. Therecirculated air is mixed with the outside air in a mixing chamber.Mixing of the heated air and outside cool air is maximized in a passivemanner via the use of one or more turbulators or elongate members, whichis a component that is designed to increase turbulent flow of air withinthe mixing chamber and prevent temperature based airflow stratification.The turbulators may be projections, arms, or other members, that projector extended into the mixing chamber. The surface of the turbulators maybe designed to induce turbulent airflow.

Having described several features of the system and method generally,additional aspects and features will be readily apparent in view of thedescription of the various drawings provided herein below.

Referring now to FIG. 1, illustrated is an embodiment of a system thatis designed to cool computing devices within a facility 100. Thefacility 100 includes a plurality of exterior walls 102 that define theexterior surface of the structure. The facility 100 includes one or moresections 110, and commonly a plurality of sections 110, in which eachsection 110 is partitioned or divided from an adjacent section 110 andin which each section 110 is designed to cool computing devices withinthe respective section. FIGS. 2-6 illustrate the sections in greaterdetail, but as illustrated in FIG. 1, each section 110 typicallyincludes a first air inlet 212, a second air inlet 214, and an airoutlet or exhaust 220. The system is essentially modular and thefacility 100 may have a length L that is as short as a single section(e.g., 10-12 feet) or that is as long as desired, such as 300 feet ormore. The sections 110 in the facility 100 commonly have identicalconfigurations, however, one or more sections 110 within the facility100 may differ from another section as desired. For example, a facility100 may include one or more sections having the configurationillustrated in FIG. 2 and may also include one or more sections havingthe configuration illustrated in FIG. 6.

As illustrated in FIG. 2, each section 110 has a symmetric design sothat the first air inlet 212, second air inlet 214, exhaust 220,computing devices 240, etc. are essentially mirrored about a midpoint ofthe facility 100. The facility 100 has a width W that may be selected asdesired or needed, and which is commonly between 30 and 60 feet, andmore commonly between 40 and 50 feet. The facility 100 likewise has aheight H that may be selected as desired or needed, and that is commonlybetween 40 and 50 feet so that the facility 100 is essentially a fourstory building. In such instances, two of the stories may include thecomputing devices, a third story may be a space for recirculated exhaustair, and a fourth story may be, or include, the exhaust air outlet 220.It should be realized that the configuration of the facility 100 may bevaried depending on need or other conditions.

The facility 100 is oriented in relation to the environment so that theexhaust air is blown away from the facility 100. Specifically, thefacility 100 is oriented so that the common prevailing winds aredirected to flow along a longitudinal side, or along both longitudinalsides, of the facility 100. This orientation ensures that most or all ofthe exhaust air does not mix with the ambient or fresh outside air inthe environment. Since the exhaust air does not mix with the ambientfresh outside air, the exhaust air is not unintentionally recirculatedinto the facility 100 via the air inlet 212, which unintentional mixingmay raise the temperature of the fresh outside air to an undesirablelevel, such as above 90 to 100 degrees or more. Positioning of theexhaust outlet 220 at or near the top of the facility 100 aids inensuring that the exhausted air does not unintentionally mix with thefresh outside air.

The facility 100 is similarly oriented so that the exhaust is blown awayfrom other adjacent facilities (not shown) so as to avoid unintentionalmixing of the exhaust air with the fresh outside air that is adjacent toan neighboring facility. In some instances, it may be desirable toensure that the facility 100 is located in an area that commonlyexperiences a modest wind, such as between 2-10 miles per hour (mph) orbetween 4-6 mph. The modest wind may ensure that the exhaust air isblown away from the facility 100 without being overly disruptive to thecirculation of air within the facility 100. In selecting a location forthe facility 100, and/or an orientation of the facility 100 within agiven location, historical weather data may be analyzed to determinecommon weather conditions (e.g., wind direction, wind speed, high andlow temperatures, humidity levels, etc.) within the location to ensurethat the location is proper for the passive cooling that the systememploys. If the common temperature is too hot, too humid, too windy, andthe like, the location may not be suitable for the passive coolingsystem described herein.

The system may be designed to accommodate local isolated changes inweather. For example, if the local wind is flowing in a moreperpendicular direction relative to the longitudinal sides of thefacility 100, one or more vents or louvers on the first air inlet 212and/or second air inlet 214 on the upwind side of the facility 100 maybe closed to reduce air pressure on the upwind side of the facilityand/or to reduce air swirling or air vortices within the facility 100.The closing of the vents or louvers may also be used to prevent a vacuumfrom being created on an opposite side of the facility 100. In someinstances, baffling may be used with the vents or louvers, or in placeof the vents or louvers, to counteract prevailing winds.

Referring now to FIGS. 2 and 3, illustrated is an embodiment of asection 110 of the facility 100. The section 110 may be any width, butis more commonly between 10-12 feet wide. As briefly described, thefacility 100 may include one or more of the sections 110, of which thesection 110 of FIGS. 2 and 3 is a representative example. FIG. 2 is across sectional view of the facility 100 and illustrates an entiresection 110 while FIG. 3 is perspective view of half of the section 110.FIGS. 2 and 3 also illustrate the interior space of the facility 100 andthe various components that are positioned within the interior space. Inparticular, the section 110 includes a supply air space, or cool airaisle, that is defined as the space between the first air inlet 212, thesecond air inlet 214, and the computing devices 240. The supply airspace, or cool air aisle, includes a mixing chamber 216 and a computingspace 256. The computing space 256 is partitioned or divided from themixing chamber 216 by an interior wall 228 and filter structure 222. Thesupply air space, or cool air aisle, includes cool air Tc that issupplied to the computing devices 240 to cool the computing devices 240during operation of the devices. The cool air Tc is typically outsideair that is supplied through the first or second air inlets, 212 and214, which may or may not be mixed with exhaust air as described herein.

The section 110 also includes an exhaust air space, or hot air aisle,that is defined as the space between the computing devices 240, a mixingdamper 232, and the exhaust air outlet 220. The exhaust air space, orhot air aisle, includes a main exhaust air space 254, a recirculated hotair space 258 (hereinafter recirculated air space 258), and a vent airspace 252. The exhaust air space, and in particular the main exhaust airspace 254 and the vent air space 252, are configured to exhaust heatedair Tx from the computing devices 240 to the external environment viaexhaust outlet 220. The recirculated air space 258 is typicallypositioned above the computing space 256 and is partitioned or dividedfrom the computing space 256 via a floor 236. The floor 236 is a solidfloor material that is impermeable to air in order to ensure that thecool air Tc does not flow into the recirculated air space 258.

The recirculated air space 258 is also divided from the mixing chamber216 via a mixing damper 232 that is positioned on an exterior end of therecirculated air space 258. In some embodiments, a wall or otherpartition may extend vertically upward from the mixing damper 232 todivide the recirculated air space 258 from the mixing chamber 216. Asdescribed in greater detail herein, the mixing damper 232 may be openedto allow exhaust air TH to flow into the mixing chamber 216 for mixingwith the cool air Tc, or the mixing damper 232 may be closed to preventthe heated air TH from flowing into the mixing chamber 216. In thismanner, the mixing damper 232 is operable to control an amount ofexhaust air TH that is supplied from the main exhaust air space 254 tothe supply air space for mixing with the cool air Tc supplied throughthe first air inlet 212. The mixing damper 232 may have variousdimensions, but is commonly between 3 and 8 feet high and 4-12 feetwide. In a specific embodiment, the mixing damper 232 is approximately 4feet high and 8 feet wide.

The vent air space 252 may be divided from the main exhaust air space254 via a damper or vent 250, which may be opened to allow the heatedair TH to vent to the external environment or that may be partially orfully closed to force heated air TH into the recirculated air space 258for mixing with the cool air Tc. The damper 250 and/or exhaust outlet220 may be similarly sized to the mixing damper 232, although the damper250 is typically larger than the exhaust outlets 220 due to the damper250 typically venting considerably more air than either exhaust outlet220. In some embodiments the damper 250 may not be included in thesection 110. Rather, the section 110 may only include the exhaust outlet220. In other embodiments, the section 110 may not include the exhaustoutlet 220 and instead may only include the damper 250, which may beused to control and regulate exhausting of the heated air TH and/orrecirculation of the heated air TH within the section 110. When thesection 110 includes both the damper 250 and the exhaust outlet 220,louvers or other airflow control are typically only included in thedamper 250 and the exhaust outlet 220 is open. The vent air space 252typically has a width that corresponds to the width of the main exhaustair space 254 or is slightly larger than the main exhaust air space 254.In a specific embodiment, the vent air space 252 has a width ofapproximately 13 feet. The vent air space 252 may be designed to vent aconsiderable amount of air, such as between 40,000 and 60,000 cubic feetper minute (CFM) of exhaust air TH. Accordingly, the height and width ofthe vent air space 252 and the size of the damper 250 and/or exhaustoutlets 220 are typically selected to vent this volume of air, althoughthe exact dimensions may be selected to vent less air as required by thedesign and intended use of the section 110. The pitch of the roof abovethe vent air space 252, and/or in other portions of the section 110, maybe 5/12 pitch.

A space 230 between the recirculated air space 258 and the main exhaustair space 254 is open so that the recirculated air space 258 is in fluidcommunication with the main exhaust air space 254. The open space 230ensures that the heated air TH is able to flow from the main exhaust airspace 254 to the recirculated air space 258 and to the mixing damper232. A vertically oriented parapet or partition 234 extends upward fromthe floor 236 of the recirculated air space 258 to partially divide orpartition the recirculated air space 258 from the main exhaust air space254. The partition 234 aids in guiding the heated air TH in a verticaldirection and minimizes the formation or vortices that may otherwiseoccur in the recirculated air space 258 and in which the heated air THmay continuously circulate. The partition 234 may extend upward from thefloor 236 between 1 and 6 feet, and more commonly between 2 and 4 feet.

The computing devices 240 partition the computing space 256 from themain exhaust air space 254. The computing devices 240 form a wallbetween the computing space 256 and the main exhaust air space 254, orare positioned or housed on a wall between the computing space 256 andthe main exhaust air space 254. A distance between opposing walls of thecomputing devices 240 may be between 5 and 20 feet, but is more commonlybetween 10 and 14 feet. In a specific embodiment, the distance betweenopposing walls of the computing devices 240 is approximately 12 feet.The main exhaust air space 254 may similarly be between 5 and 20 feet,and more commonly between 10 and 14 feet. In a specific embodiment, themain exhaust air space may be approximately 12 feet. The main exhaustair space 254 is also typically between 15 and 50 feet tall, and morecommonly between 20 and 40 feet tall.

At least some of the computing devices 240 include a fan that is capableof moving the cool air Tc across one or more heat generating componentsof the computing devices 240 to cool the heat generating components. Insome embodiments, most of the computing devices 240, or all of thecomputing devices 240, include a fan that moves the cool air Tc acrossthe heat generating component(s). Each of the fans is oriented so thatthe air flows from the computing space 256 to the main exhaust air space254. The computing devices 240 are oriented or arranged relative to oneanother, and/or in relation to the wall that partitions the computingspace 256 from the main exhaust air space 254, so that the air is ableto flow from the computing space 256 into the main exhaust air space254, but is prevented from flowing from the main exhaust air space 254into the computing space 256. Stated differently, the computing devices240, and/or wall, partition the computing space 256 from the mainexhaust air space in a relatively air tight manner so that a flow of airfrom the main exhaust air space 256 to the computing space 254 isnegligible. In this manner, the cool air Tc is forced across the heatgenerating component(s) of the computing devices 240 and is heated bythe heat generating component(s). The heated air Tx flows into the mainexhaust air space 254 and is exhausted from the section 110 or isrecirculated within the section 110 as described herein.

The dimensions of the computing space 256 may be varied as desired. Forexample, in some embodiments the computing space 256 may be a singlefloor or story of the section 110, while in other embodiments, thecomputing space 256 may be multiple floors or stories of the section110. In FIGS. 2 and 3 the computing space 256 is two floors or storiesof the facility 100 and is roughly 10-12 feet wide and 15-22 feet high.The computing devices 240 may be arranged in any manner within thecomputing space 256, but are more commonly arranged in rows and columns.The computing space 256 may include essentially any number of computingdevices, such as between 50 and 200 devices, although between 120 and180 computing devices is more common. In the illustrated embodiment,each row includes roughly 12 computing devices and the computing space256 includes approximately roughly 14 rows. This arrangement results inroughly between 150 and 170 computing devices, although this arrangementis for illustrative purposes only and is not meant to be limiting in anymanner. As a person of skill will readily recognize, more or fewercomputing devices may be employed as desired and the arrangement andnumber is dependent in part on the size of the computing devices.

As briefly mentioned above, airflow through the section 110 issubstantially driven by the combined airflow of a plurality of thecomputing device fans. More commonly, the airflow is driven entirely bythe fans of the computing device so that the section 110 is free of anyother air moving device, such as a dedicated fan or blowing mechanism.Stated differently, the computing device fans may be the only devices ormechanisms within the section 110 that move or blow the air through thesection 110. While the fans of each computing device 240 are typicallyutilized to drive airflow through the section 110, the system does notrequire that the fan of each computing device 240 be operated to drive asufficient airflow through the section 110. Rather, it should beappreciated that some of the fans may not be operated and/or that someof the computing devices 240 may not include fans or other air movingdevices or components at all. All of the computing device fans, orsubstantially all of the computing device fans, are typically operatedto move air through the section 110 since the operation of less than100% of the fans may create areas where backflow occurs, such as theexhaust air flowing backward into the computing device space. Thecomputing devices 240 may be robust machines that are tolerant tovariations in the temperature and thus, changes in airflow due to theamount of fans being used to drive the airflow may not substantiallynegatively impact the operation of the computing devices 240.

The combined effect of the computing device's fans may result in aconsiderable volume of air being moved through the section 110. Forexample, the combined computing device fans may move more than 10,000CFM of air through the section 110. The section 110 design that isillustrated in FIGS. 2 and 3 may move between 40,000 and 60,000 CFM ofair through the section. In a specific embodiment, the section 110 ofFIGS. 2 and 3 may move approximately 54,000 CFM of air with each half ofthe section 110 moving approximately 27,000 CFM of air. The exhaustoutlet 220, damper 250, mixing damper 232, and/or first and second airinlets, 212 and 214, are sized to accommodate this large volume of airmovement. Each of these components may be configured to allow airflowthrough the respective component at an airspeed of between 300 and 600feet per minute, and more commonly between 400 and 500 feet per minute.

As briefly mentioned above, cool air Tc is able to flow into the section110 via the first air inlet 212 and the second air inlet 214. The firstand second air inlets, 212 and 214, may have various dimensions, but arecommonly between 3-5 feet high and 8-12 feet wide. In a specificembodiment, the first and second air inlets, 212 and 214, areapproximately 4 feet high and 8 feet wide. The second air inlet 214 ispositioned vertically below the first air inlet 212.

The first air inlet 212 typically does not include a damper or otherclosable vent and as such, outside air is essentially always able toflow through the first air inlet 212 into the interior of the section110. However, the first air inlet 212 typically does include a staticlouver, mesh screen, or other component that prevent animals or debrisfrom accessing the interior of the section 110. Unlike the first airinlet 212, the second air inlet 214 includes a damper or closable vent.The damper is used to open the second air inlet 214 when airflow throughthe second air inlet 214 is desired and is also used to close the secondair inlet 214 when airflow through the intake is not desired. The dampermay be partially or fully closed to control the flow of air through thesecond air inlet 214. The damper is commonly closed when the mixingdamper 232 is opened to combine the heated air TH with the cool air Tc.The degree of closure of the second air inlet's damper may be correlatedwith the degree of openness of the mixing damper 232 to achieve adesired mixing ratio of heated air TH and cool air Tc. In this manner, afinite and constant amount of air may flow into and through the mixingchamber 216. The opening and closing of the second air inlet's damper isfurther described in relation to FIGS. 4-5.

An air filter 222 is positioned between the mixing chamber 216 and thecomputing space 256. The air filter 222 is configured to filter the coolair Tc that is supplied through the first and/or second air inlets, 212and 214. The air filter 222 is illustrated as being a vertical wall thatis coupled with a bottom end of the interior wall 228 and a floor of thefacility 100, but the air filter 222 may be placed essentially anywherebetween the mixing chamber 216 and the computing space 256 and/or haveany orientation desired. The air filter 222 is commonly 8-12 feet wideand approximately 6-12 feet tall. The width and height of the air filter222 may be varied depending on a required or desired pressure drop withlarger cross-sectional areas of the filter 222 resulting in a lowerpressure drop. The air filter 222 may be aligned with the second airinlet 214 so that when opened, air is able to flow directly from thesecond air inlet 214 and through the air filter 222. Alignment of theair filter 222 and the second air inlet 214 is not required in thesection 110.

The air filter 222 is commonly an accordion or pleated filter, whichmaximizes the available surface area for filtering the cool air Tc andminimizes the pressure drop or loss across the air filter 222. Since theairflow through the systems is dependent mostly or entirely on thecombined airflow of the computing device's fans, minimizing the pressuredrop across the air filter 222 is more important than in conventionalsystems that have dedicated high output fans or blower mechanisms. Anair filter 222 that is designed to remove debris or particles too smallmay overly burden the computing device's fans, which may cause thecomputing devices 240 to prematurely fail. An air filter with a minimumefficiency reporting value (MERV) rating of between 7-8 has been foundto provide a sufficient degree of air filtering and an acceptablepressure drop. Accordingly, the air filter 222 commonly has a MERVrating of between 7 and 8. As illustrated in FIGS. 2 and 3, in someembodiments, only a single air filter 222 is employed to filter the coolair Tc. In other embodiments, additional air filters may be employed andpositioned within the section 110 to filter the cool air Tc. The use ofmultiple filters may reduce the MERV rating that is required for asingle air filter.

The mixing shaft or chamber 216 is positioned downstream of the firstair inlet 212 and the mixing damper 232. The mixing chamber 232 isconfigured to create turbulent airflow as the air flows verticallydownward through the mixing chamber 232. The turbulent airflow promotesand substantially increases mixing of the exhaust air TH and cool airTc. Without turbulence in the mixing chamber 216, the airflow maystratify, resulting in a layer of exhaust air TH and cool air Tc withlittle intermixing between the layers due to temperature based airflowstratification. Stratified airflow may result in drastic temperaturedifferences in the air that is supplied to the computing devices 240 tocool the devices, which may lead to overheating or overcooling somedevices. To create turbulent airflow within the mixing chamber 212, themixing chamber 212 includes a plurality of turbulators or elongatemembers 218 that project into the mixing chamber 216. The elongatemembers 218 may be relatively long and thin components that project orextend into the mixing chamber 216. In some embodiments, the elongatemembers 218 may be between 2 and 12 feet long, and more commonly between4 and 10 feet long. The elongate members 218 may also be between 3 and12 inches wide and more commonly between 4 and 8 inches. Various otherdimensions for the elongate members 218 may also be employed. Each ofthe elongate members 218 may have a uniform or similar configuration ormay have different configurations—either in size and/or orientationwithin the mixing chamber 216. Differently sized and/or orientedelongate members 218 within the mixing chamber 216 may increase theturbulence that is created within the mixing chamber 216.

In some embodiments, opposing ends of the elongate members 218 may beattached to opposing, or different walls, within the mixing chamber 216.In such embodiments, a middle portion of the elongate members 218 mayproject into the interior of the mixing chamber 216. In otherembodiments, a single end of the elongate member 218 may be attached toa wall of the mixing chamber 216. In such embodiments, the other end ofthe elongate member 218 may terminate within the mixing chamber 216. Themixing chamber 216 may include a combination of elongate members 218that are attached at opposing ends with the walls of the mixing chamber216 and elongate members 218 that are attached at only one end with awall of the mixing chamber 216. Similarly, the elongate members 218 maybe diagonally oriented within mixing chamber 216 or may have otherorientation, such as substantially horizontal. The orientation of theelongate members 218 within the mixing chamber 216 is typically randomto increase the turbulent flow of air through the mixing chamber 216. Assuch, some of the elongate members 218 are commonly more horizontallyoriented in comparison with other elongate members 218 within the mixingchamber 216.

The elongate members 218 are passive devices, which means that they arenot electrically or mechanically moved within the mixing chamber 216.Rather, they are static objects that are strategically positions toforce the air to pass and flow around the objects.

The flow of air around the objects causes turbulent airflow as opposedto laminar airflow, which substantially increases the mixing of theair—i.e., cool air Tc and exhaust air Tx—within the mixing chamber 216as the air flows downward and through the mixing chamber 216. In someembodiments, the exterior surface of the elongate members 218 may beconfigured to increase the turbulent airflow. For example, the exteriorsurface may be textured, rough, or otherwise configured to increase skinfriction or drag, which may greatly increase the turbulent flow in themixing chamber 216. In some embodiments the mixing chamber 216 may beroughly 8 feet wide per unit length, although the size of the mixingchamber 216 may be varied as desired or required. In some embodiments,the right side of chamber 216 may be compartmentalized. The elongatemember 218 are further configured so that when the mixing damper 232 isclosed and the first and second air inlets, 212 and 214, are open, theelongate members 218 do not impede the flow of air through the section.

Referring now to FIG. 6, illustrated is another embodiment of a section110 that may be employed within a facility 100. The section 110 issubstantially similar to the section 110 illustrated in FIGS. 2 and 3except that the damper 250 is removed and the section 110 includes twofloors of computing devices. Specifically, the section 110 includes afirst computing floor 256 a having a first wall of computing devices 241and a second computing floor 256 b having a second wall of computingdevices 242. The first computing floor 256 a is separated from thesecond computing floor 256 b by a floor, which may be made of an airpermeable material, such as a mesh type material. As such, the cool airTc is able to flow between the first computing floor 256 a and thesecond computing floor 256 b relatively unobstructed. Additional airfilters, 224 and 226, may optionally be positioned to filter the coolair Tc that flows into the first computing floor 256 a and the secondcomputing floor 256 b. The additional air filters, 224 and 226, mayextend between the floor 236 and the floor of the facility and may becoupled with the floor that separates the first computing floor 256 aand the second computing floor 256 b. The additional air filter, 224 and226, may also sized and/or configured similar to the air filter222—e.g., may have a similar MERV rating.

In some embodiments, the wall that is formed or defined by the secondcomputing devices 242 (hereinafter second wall) is laterally offset fromthe wall that is formed or defined by the first computing devices 241(hereinafter first wall). For example, the second wall may be laterallyoffset from the first wall by between 6 and 24 inches and more commonlyabout 18 inches. When a width between the opposing first walls is 12feet as described above, an offset of 18 inches between the second walland the first wall would result in a width between the opposing secondwalls of approximately 15 feet. The offset between the first wall andthe second wall may be selected as desired and may be used toaccommodate an extra volume of heated air that flows upward toward theexhaust outlet 220 from the second walls. While FIG. 6 only illustrates½ of the section 110, it should be appreciated that the othernon-illustrated half typically has a mirrored configuration to theillustrated section. [0045] Referring now to FIG. 4, illustrated is theairflow through the section 110 of FIGS. 2 and 3 in which exhaust air262 is not recirculated within the section 110. The airflow that isillustrated in FIG. 4 may correspond to a typically airflow through thesection 110 in warmer months in which the outside air is cool enough tocool the computing devices 240, but not too cold to require mixing ofthe heated exhaust air 262 and not to humid to require mixing of theheated exhaust air 262. In the illustration of FIG. 4, the exhaustoutlet 220 and/or damper 250 are maintained fully open so thatsubstantially all of the exhaust air 262 is exhausted or vented to theexternal environment. The exhaust air 262 is illustrated as flowingupward from the computing devices 240 and out of the damper 250 andexhaust outlet 220. The mixing damper 232 is maintained closed so thatsubstantially none of the exhaust air 262 flows into the mixing chamber216 as illustrated in FIG. 4.

The second air inlet 214 is maintained fully open so that the cooloutside air 260 (hereinafter cool air 260) is able flow through both thefirst air inlet 212 and the second air inlet 214. Each of the airinlets, 212 and 214, are sized so that approximately ½ of the air volumeflows through each air inlet. The cool air 260 flows through the airinlets and through the filter 222 to the computing devices 240 where thecool air 260 is warmed by the heat generating components. The heatedcool air 260 then flows into the main exhaust air space 254 as exhaustair 262. The airflow through the system is typically driven entirely bythe fans of the computing devices 240 as previously described, althoughin some embodiments one or more dedicated fans or blowing mechanism mayaid in moving the air through the system.

It should be appreciated that FIG. 4 is provided for illustrativepurposes and that the second air inlet 214, the exhaust outlet 220,and/or the damper 250 may be incrementally or partially closed so thatonly some fraction of a maximum airflow of cool air 260 is deliveredthrough the second air inlet 214 and so that some fraction of a maximumairflow of exhaust air 262 is vented from the facility. The mixingdamper 232 may likewise be incrementally or partially opened so thatsome fraction of a maximum airflow of exhaust air 262 is deliveredthrough the mixing damper 232 to the mixing chamber 216 for mixing withthe cool air 260 that flows through the first air inlet 212.

The dimensions of the section 110 are typically dependent on the desiredor required airflow through the system. For example, the size of themain exhaust air space 254, the size of the air filter 222, and the sizeof the air inlets, dampers, and outlets are all dependent on the airflowthat is expected within the section 110. For example, as describedabove, the section 110 may be configured to accommodate an airflow ofapproximately 54,000 CFM, or 27,000 CFM for ½ of the section 110. Giventhis airflow, the exhaust outlet 220 should be capable of venting orexhausting all of the airflow (e.g., 27,000 CFM at around 500 feet perminute) since in some embodiments all of the exhausted air will bevented from the facility 100. The exhaust outlet 220 may be roughly 8feet wide and 7 feet tall to exhaust this volume of air at the desiredair speed.

The first air inlet 212 is typically sized smaller than the exhaustoutlet 220 since the volume of air that flows through the first airinlet 212 is typically less than the volume of air that flows throughthe exhaust outlet 220 due to the use of the second air inlet 214 and/orthe mixing damper 232. The first air inlet 212 is commonly an openpenetration with a mesh guard and no movable louvers. The first airinlet 212 typically remains open regardless of the external weatherconditions, although preparations may exist to close the first air inlet212 when necessary. The second air inlet 214 is also typically sizedsmaller than the exhaust outlet 220 since the volume of air that flowsthrough the second air inlet 214 is less than the volume of air thatflows through the exhaust outlet 220 due to the use of the first airinlet 212. A cross-sectional area of the exhaust outlet 220 willtypically be equal to or larger than a combined cross-sectional area ofthe first and second air inlets, 212 and 214, or a combinedcross-sectional area of the first air inlet 212 and the mixing damper232 since the volume of air entering and exiting the section 110 must beequal. A cross-sectional area of the first air inlet 212, the second airinlet 214, and the mixing damper 232 is roughly equal since roughly halfof the air entering the section 110 is provided by the first air inlet212 and the other half of the air entering the section 110 is providedby the second air inlet 214, the mixing damper 232, or a combination ofthe second air inlet 214 and mixing damper 232. A cross-sectional areaof the damper 250 is twice the size of the cross-sectional area of theexhaust outlet 220 or larger since the damper 250 is used to ventexhaust air from both sides of the section and to vent exhaust air to apair of exhaust outlets 220—i.e., the damper 250 accommodates both sidesof the section 110. The second air inlet 214 includes louvers, closablevents, or other components that allow the second air inlet 214 to bepartially or fully closed to impede or prevent airflow through thesecond air inlet 214. The louvers may be electronically controlledvariable frequency drive components.

The first and second air inlets, 212 and 214, may each be sized so thatapproximately 50% of the maximum air flow of the exhaust outlet 220(e.g., 27,000 CFM) is deliverable through each air inlet. Using theexample above, approximately 13,500 CFM of airflow may be deliveredthrough the first air inlet 212 and an additionally 13,500 CFM may bedelivered through the second air inlet 214. The airflow may be providedat a max air speed of around 421 feet per minute, which is roughlyapproximate to the max air speed through the exhaust outlet 220. Thefirst and second air inlets, 212 and 214, may be roughly 8 feet wide and4 feet tall to deliver this desired air flow.

As briefly described above, the mixing damper 232 may be opened and thesecond air inlet 214 may be closed to force some of the exhaust air 262to flow through the mixing damper 232 and into the mixing chamber 216,where it is mixed with the cool air 260. The mixing damper 232 and thesecond air inlet 214 may be paired so that the degree of closure of thesecond air inlet's damper may be correlated with the degree of opennessof the mixing damper 232. The pairing of the mixing damper 232 andsecond air inlet 214 allows a desired mixing ratio of cool air 260 andexhaust air 262 to be achieved. In some embodiments, the mixing damper232 and the second air inlet 214 are paired in a 1 to 1 ratio so thatopenness of one component directly corresponds to the closure of theother component. For example, when the mixing damper 232 is 25% open,the second air inlet 214 may be 25% closed and when the mixing damper232 is 75% open, the second air inlet 214 may be 75% closed. The amountof openness of one component and the amount of closure of the othercomponent may vary by any amount between 0% and 100%. As such, someamount or volume of air may simultaneously flow through the first airinlet 212, the second air inlet 214, and the mixing damper 232.

The damper 250 or exhaust outlet 220 may also be partially closed toincrease air pressure within the main exhaust air space 254 and withinthe recirculated air space 258 and thereby force the exhaust air 262through the mixing damper 232. In some embodiments, the degree ofclosure of the damper 250 or exhaust outlet 220 may be correlated withthe degree of openness of the mixing damper 232 and the degree ofclosure of the second air inlet 214. The damper 250 is typicallyemployed to regulate the airflow through the mixing damper 232. In aspecific embodiment, the degree of closure of the damper 250 may becorrelated with the degree of openness of the mixing damper 232 so thatthe damper 250 closes roughly ½ of the amount that the mixing damper 232opens. This degree of closure of the damper 250 may create the necessaryback pressure to develop within the recirculated air space 258 to forcethe exhaust air 262 to flow through the mixing damper 232 and into themixing chamber 216. As previously described, the second inlet 214 mayalso close by the same amount that the mixing damper 232 opens, whichlikewise aids in forcing the exhaust air 262 to flow through the mixingdamper 232 and into the mixing chamber 216. In some embodiments, theexhaust outlet 220 may be partially or fully closed without opening themixing damper 232 in order to increase an internal temperature withinthe section 110 and facility 100.

The mixing damper 232 may be opened to recirculate the exhaust air 262within the system in order to increase the temperature of the cool air260, such as during the winter months, or to reduce a humidity in thecool air 260, such as during humid conditions in the warmer months. Themixing damper 232, second air inlet 214, and exhaust damper 220 aretypically controlled via a control system (not shown) of the facility100. The control system includes a processor, memory, and one or moresensors that are configured to sense conditions within the facility 100and/or external to the facility 100, such as the cool air temperature,the external humidity levels (relative and/or absolute humidity), theinternal air temperature, the internal humidity levels (relative and/orabsolute humidity), the airflow through the facility, the exhaust gasair temperature, the pressure differential within the system and/oracross one or more components, and the like. The sensors communicatethis information to the processor and the processor analyzes theinformation and responds accordingly by opening or closing the variousdampers, vents, outlets, and intakes. For example, when the processordetermines that the cool air 260 is too cold, the processor responds bysending appropriate instructions to open the mixing damper 232 andsimultaneously close the second air inlet 214 and/or exhaust outlet 220.A similar process may occur when the processor determines that therelative humidity in the air is too high. Conversely, when the processordetermines that the internal air is too hot and/or the cool air is cool,but not too cold, the processor responds by sending appropriateinstructions to close the mixing damper 232 and open the second airinlet 214 and/or exhaust outlet 220. In this manner, the control systemis able to modulate the conditions within the facility via informationabout the cool air and weather conditions and/or via information aboutthe conditions within the facility 100. The control system, includingthe processor and memory, may be an onsite system that is housed withinor near the facility 100 or may be a remote system, such as a cloudcomputing based system. The control system may monitor one or morefacilities and one or more sections within each facility and modulatethe conditions within each section and within each facility as needed.

In regards to the mixing damper 232, the mixing damper typicallyincludes electronically controlled louvers that have a variablefrequency drive capability. The mixing damper 232 may be sized to ventroughly 60% of the maximum air flow of the exhaust outlet 220 (e.g.,27,000 CFM). The airflow through the mixing damper 232 may be providedat a max air speed of around 500 feet per minute, which is roughlyapproximate to the max air speed through the exhaust outlet 220. Usingthe example above of an airflow of 27,000 CFM through the exhaust outlet220, the mixing damper 232 may be configured to vent approximately16,200 CFM of air. The mixing damper 232 may be roughly 8 feet wide and4 feet tall to deliver this desired air flow.

As briefly described above, the mixing damper 232 may be opened toincrease the temperature of the cool air 260 and/or to reduce a relativehumidity of the cool air 260. For example, if the outside airtemperature is 40 degrees Fahrenheit, the mixing damper 232 may beopened to allow the exhaust air 262 to flow into the mixing chamber 216and mix with the cool air 260. Regardless of the temperature of theexhaust air 262, the system may expose the cool air 260 to the exhaustair 262 via the mixing damper 216 to achieve a desired treated aircondition, such as a temperature that is effective to cool the computingdevices to between 60 and 90 degrees Fahrenheit in accordance withASHRAE TC9.9 environmental standards. The mixing damper 232 may beincrementally closed and/or the second air inlet 214 may beincrementally opened as the outside air temperature nears an idealcooling temperature, such as a temperature that is effective to cool thecomputing devices to between 60 and 90 degrees Fahrenheit in accordancewith ASHRAE TC9.9. When the outside air temperature reaches the idealcooling temperature, the mixing damper 232 may be fully closed so thatthe system is cooled entirely by the outside air. Similarly, as theoutside air temperature drops below the ideal cooling temperature, themixing damper 232 may be incrementally opened and/or the second airinlet 214 may be incrementally closed until the mixing damper is fullyopened and/or the second air inlet is fully closed. The relativelyhumidity in the air may likewise be reduced via the introduction of theexhaust air 262 to the cool air 260. In this manner the humidity of thecool air 260 may be modulated to a level that is in accordance withASHRAE TC9.9 environmental standards.

Referring now to FIG. 5, illustrated is the airflow through the section110 of FIGS. 2 and 3 in which the exhaust air 262 is recirculated withinthe section 110. The airflow that is illustrated in FIG. 4 maycorrespond to a typically airflow in the cooler or cold months in whichthe cool air 260 is too cold to adequately cool the computing devices240, or in which the cool air 260 is below an ideal cooling temperature.The relative humidity of the cool air 260 is typically not a concernduring this time period since the cool air 260 will be warmed by theexhaust air 262. In the illustration of FIG. 5, the exhaust outlet 220and/or damper 250 are fully closed so that substantially all of theexhaust air 262 flows into the recirculated air space 258 and throughthe mixing damper, which is illustrated as being fully opened. Theexhaust air 262 is illustrated as flowing upward and into therecirculated air space 258 and through the mixing damper 232 into themixing chamber 216.

The second air inlet 214 is fully closed so that substantially none ofthe cool air 260 is able flow through the second air inlet 214 andinstead is forced to flow through the first air inlet 212. The cool air260 is forced to flow through the first air inlet 212 so that the coolair 260 and the exhaust air 262 are subjected to the mixing chamber 216and the elongate members 218, which mixes the cool air 260 and theexhaust air 262 via the passive creation of turbulent flow. If thesecond air inlet 214 were opened, a substantial portion or volume of thecool air 260 would flow through the second air inlet and may notproperly mix with the exhaust air 262. The mixed cool air 260 andexhaust air 262 (hereinafter heated air 264) flows through the airfilter 222 to the computing devices 240 where the heated air 264 coolsthe heat generating components as the heated air 264 flows through thecomputing devices 240 and into the main exhaust air space 254. Theheated air 264 is further heated by the heat generating components andenters the main exhaust air space 254 as exhaust air 262. The airflowthrough the system is typically driven entirely by the fans of thecomputing devices 240 as previously described, although in someembodiments one or more dedicated fans or blowing mechanisms may aid inmoving the air through the system.

As previously described, it should be appreciated that FIG. 5 isprovided for illustrative purposes and that the second air inlet 214,the exhaust outlet 220, and/or the damper 250 may be incrementally orpartially opened so that some fraction of a maximum airflow of cool air260 is delivered through the second air inlet 214 and so that somefraction of a maximum airflow of exhaust air 262 is vented from thefacility. The mixing damper 232 may likewise be incrementally orpartially closed so that some fraction of a maximum airflow of exhaustair 262 is delivered through the mixing damper 232 to the mixing chamber216 for mixing with the cool air 260 that flows through the first airinlet 212. Thus, the flow of cool air 260, exhaust air 262, and heatedair 264 through the system may include any incremental airflowpercentage or volume between the illustrations of FIG. 4 and FIG. 5 as aperson of skill in the art will readily understand.

Referring now to FIG. 7, illustrated is a method 300 of coolingcomputing devices within a facility. As described herein, the facilityhas an interior space that includes a supply air space and an exhaustair space. At block 310, outside air flows from an external environment,through an air inlet of an exterior wall of the facility, and to thesupply air space within the facility. At block 320, the outside airflows through an air filter assembly within the facility to filter theoutside air and thereby remove unwanted particles and debris from theoutside air. At block 330, the filtered outside air flows through aplurality of computing devices in order to cool one or more heatgenerating component of the computing devices. The computing devices arearranged within the interior space of the facility so that the computingdevices partition at least a portion of the supply air space from theexhaust air space. In some embodiments, most or all of the computingdevices include a fan that is capable of moving the filtered outside airacross the one or more heat generating components to cool the heatgenerating components and heat the filtered outside air. The heated airflows into the exhaust air space from the computing devices. At block340, the heated air flows through an exhaust air damper to exhaust theheated air from the exhaust air space to the external environment. Theairflow of the outside air and the heated air is substantially driven bythe combined airflow of a plurality of the fans of the computing devicesas described herein.

At block 350, at least a portion of the heated air flows through amixing damper that is positioned within the interior space of thefacility between the supply air space and the exhaust air space. Theheated air flows through the mixing damper to enable mixing of theheated air and the outside air supplied through the air inlet. Asdescribed herein, block 350 is an optional step that may be used toincrease the temperature of the outside air and/or reduce the relativehumidity of the outside air. The interior space of the facility mayinclude a hot air space, or recirculated air space, that is positionedvertically above the computing devices. The hot air space may be influid communication with the exhaust air space so that heated air isflowable from the exhaust air space into the hot air space. The mixingdamper may be positioned on an exterior end of the hot air space. Insuch embodiments, the method 300 may also include closing the exhaustair damper and opening the mixing damper to control an amount of heatedair that flows through the mixing damper and mixes with the outside air.The facility may include two air inlets that are each configured tosupply outside air to the supply air space from the externalenvironment. A second air inlet may be positioned vertically below afirst air inlet. In such embodiments, the method 300 may further includeclosing a damper of the second air inlet to increase an amount ofoutside air that flows through the first air inlet and mixes with theheated air that flows through the mixing damper.

At block 360, the outside air and the heated air flow through a mixingshaft or chamber to create turbulent airflow and thereby promote mixingof the outside air and the heated air. Block 360 is an optional stepthat is conditioned on the occurrence of block 350. The mixing shaft mayinclude a plurality of elongate members that project into the mixingshaft to create the turbulent airflow. The mixed outside air and heatedair may flow through an air filter that is coupled with a bottom end ofthe mixing shaft and with a floor of the facility.

The computing devices may be arranged within the interior space of thefacility to form a wall that partitions the supply air space and theexhaust air space. The wall may be two stories tall and/or the facilitymay include at least two floors of computing devices. As describedherein, the facility may include two air inlets that are each configuredto supply outside air to the supply air space from the externalenvironment. A second air inlet may be positioned vertically below afirst air inlet. In such embodiments, the method 300 may further includeflowing outside air through the first air inlet and through the secondair inlet into the supply air space. A combined airflow through thefirst air inlet and through the second air inlet may be approximatelyequal to the airflow through the exhaust air damper.

While several embodiments and arrangements of various components aredescribed herein, it should be understood that the various componentsand/or combination of components described in the various embodimentsmay be modified, rearranged, changed, adjusted, and the like. Forexample, the arrangement of components in any of the describedembodiments may be adjusted or rearranged and/or the various describedcomponents may be employed in any of the embodiments in which they arenot currently described or employed. As such, it should be realized thatthe various embodiments are not limited to the specific arrangementand/or component structures described herein.

In addition, it is to be understood that any workable combination of thefeatures and elements disclosed herein is also considered to bedisclosed. Additionally, any time a feature is not discussed with regardin an embodiment in this disclosure, a person of skill in the art ishereby put on notice that some embodiments of the invention mayimplicitly and specifically exclude such features, thereby providingsupport for negative claim limitations.

Having described several embodiments, it will be recognized by those ofskill in the art that various modifications, alternative constructions,and equivalents may be used without departing from the spirit of theinvention. Additionally, a number of well-known processes and elementshave not been described in order to avoid unnecessarily obscuring thepresent invention. Accordingly, the above description should not betaken as limiting the scope of the invention.

Where a range of values is provided, it is understood that eachintervening value, to the tenth of the unit of the lower limit unlessthe context clearly dictates otherwise, between the upper and lowerlimits of that range is also specifically disclosed. Each smaller rangebetween any stated value or intervening value in a stated range and anyother stated or intervening value in that stated range is encompassed.The upper and lower limits of these smaller ranges may independently beincluded or excluded in the range, and each range where either, neitheror both limits are included in the smaller ranges is also encompassedwithin the invention, subject to any specifically excluded limit in thestated range. Where the stated range includes one or both of the limits,ranges excluding either or both of those included limits are alsoincluded.

As used herein and in the appended claims, the singular forms “a”, “an”,and “the” include plural referents unless the context clearly dictatesotherwise. Thus, for example, reference to “a process” includes aplurality of such processes and reference to “the device” includesreference to one or more devices and equivalents thereof known to thoseskilled in the art, and so forth.

Also, the words “comprise,” “comprising,” “include,” “including,” and“includes” when used in this specification and in the following claimsare intended to specify the presence of stated features, integers,components, or steps, but they do not preclude the presence or additionof one or more other features, integers, components, steps, acts, orgroups.

What is claimed is:
 1. A system for cooling computing devices within afacility having an interior space that includes a supply air space andan exhaust air space, the supply air space being configured to supplyoutside air to the computing devices to cool the computing devicesduring operation of said computing devices, and the exhaust air spacebeing configured to exhaust heated air from the computing devices to theexternal environment, the system comprising: an air inlet coupled to anexterior wall of the facility and configured to deliver outside air tothe supply air space from the external environment; an exhaust airdamper configured to exhaust the heated air from the exhaust air spaceto the external environment; a plurality of computing devices arrangedwithin the interior space so as to partition at least a portion of thesupply air space from the exhaust air space, wherein each computingdevice include an intake fan and an exhaust fan that, when operable,assist in moving the outside air across one or more heat generatingcomponents of the computing device to cool the heat generatingcomponents, wherein the intake fan is in fluid communication with thesupply air space and the exhaust fan is in fluid communication with theexhaust air space; and an air filter positioned between the supply airspace and the computing devices, the air filter being configured tofilter particulate from the outside air supplied to the computingdevices from the air supply space and further configured to provide apressure differential between the air inlet and the computing devicesbased on a cross-sectional area of the air filter, wherein an overallairflow through the system is substantially driven by a controllablecombination of airflow generated by the fans of the computing devicesand passive airflow flowing into the air inlet and flowing out of theexhaust air damper, and wherein an average temperature of the system,within a desired temperature range, is maintained by the overall airflowthrough the system.
 2. The system of claim 1, wherein one or more fansof the computing devices is not operated, or is operated at less thanfull capacity, in driving the airflow through the system.
 3. The systemof claim 1, wherein one or more of the computing devices does notinclude a fan that is capable of moving the outside air across one ormore heat generating components of the computing device.
 4. The systemof claim 1, wherein the air inlet is a first air inlet and wherein thesystem includes a second air inlet that is coupled with the exteriorwall of the facility and that is configured to supply outside air to thesupply air space from the external environment; wherein the second airinlet is positioned vertically below the first air inlet and includes adamper that is operable to control an amount of outside air that flowsthrough the second air inlet to the supply air space.
 5. The system ofclaim 1, wherein the system includes a hot air space positionedvertically above the plurality of computing devices, the hot air spacebeing in fluid communication with the exhaust air space such that heatedair is flowable from the exhaust air space to the hot air space.
 6. Thesystem of claim 5, wherein an interior end of the hot air space includesa vertically oriented partition that extends upward from a floor of thehot air space toward a ceiling of the facility and toward the exhaustair damper.
 7. The system of claim 1, wherein the plurality of computingdevices are arranged within the interior space of the facility to form awall that partitions the supply air space and the exhaust air space, thewall being two or more stories tall.
 8. The system of claim 1, furthercomprising a mixing damper positioned within the interior space of thefacility between the supply air space and the exhaust air space, themixing damper being adjustably operable to control an amount of exhaustair supplied from the exhaust air space to the supply air space andselectively operable to mix air from both the supply air space and theexhaust air space.
 9. The system of claim 8, wherein the facilityfurther comprises a mixing shaft positioned downstream of the air inletand mixing damper, the mixing shaft being configured to create turbulentairflow to promote mixing of the outside air and the exhaust air. 10.The system of claim 9, wherein the mixing shaft includes a plurality ofelongate members that project into the mixing shaft to create theturbulent airflow.
 11. The system of claim 10, wherein the air filter iscoupled with a bottom end of the mixing shaft and with a floor of thefacility.
 12. The system of claim 5, wherein a mixing damper ispositioned on an exterior end of the hot air space.
 13. The system ofclaim 1, wherein airflow from the supply air space is mixed with airflowfrom the exhaust space.
 14. A method of cooling computing devices withina facility having an interior space that includes a supply air space andan exhaust air space, the method comprising: flowing outside air from anexternal environment through an air inlet of an exterior wall of thefacility to supply the outside air to the supply air space; flowing theoutside air through an air filter to filter the outside air and therebyremove unwanted particles and debris from the outside air; configuring across-sectional area of the air filter to provide a pressuredifferential between the outside air and a plurality of computingdevices; flowing the filtered outside air through the plurality ofcomputing devices that are arranged within an interior space of thefacility so that the computing devices partition at least a portion ofthe supply air space from the exhaust air space, wherein substantiallyeach of the computing devices includes at least one fan, when operable,that is capable of moving the filtered outside air across one or moreheat generating components of the computing devices to remove heat fromthe heat generating components and move the heated air into the exhaustair space from the computing devices; and flowing the heated air throughan exhaust air damper to exhaust the heated air from the exhaust airspace to the external environment, wherein an overall airflow throughthe facility is substantially driven by a controllable combination ofairflow generated by the fan or fans of each of the computing devicesand passive airflow flowing into the air inlet and flowing out of theexhaust air damper, and wherein an average temperature of the facility,within a desired temperature range, is maintained by the overall airflowthrough the facility.
 15. The method of claim 14, further comprisingflowing at least a portion of the heated air through a mixing damperpositioned within the interior space of the facility between the supplyair space and the exhaust air space to mix the heated air and theoutside air supplied through the air inlet.
 16. The method of claim 15,further comprising closing the exhaust air damper and opening the mixingdamper to control an amount of heated air that flows through the mixingdamper and mixes with the outside air.
 17. The method of claim 16,wherein the air inlet is a first air inlet and wherein the facilityincludes a second air inlet that is configured to supply outside air tothe supply air space from the external environment, the second air inletbeing positioned vertically below the first air inlet, and wherein themethod further includes closing a damper of the second air inlet toincrease an amount of outside air that flows through the first air inletand mixes with the heated air that flows through the mixing damper. 18.The method of claim 15, wherein the interior space of the facilityincludes a hot air space positioned vertically above the plurality ofcomputing devices, the hot air space being in fluid communication withthe exhaust air space such that heated air is flowable from the exhaustair space to the hot air space, and wherein the mixing damper ispositioned on an exterior end of the hot air space.
 19. The method ofclaim 14, further comprising flowing the outside air and the heated airthrough a mixing shaft to create turbulent airflow and thereby promotemixing of the outside air and heated air.
 20. The method of claim 19,wherein the mixing shaft includes a plurality of elongate members thatproject into the mixing shaft to create the turbulent airflow.